VDV Voice Systems 5

Question 1

Which standard defines Power over Ethernet delivering up to 30 watts per port?

Accepted Answer

IEEE 802.3at

Answer

IEEE 802.3at (PoE+) defines delivery of up to 30 watts per port, which supports higher-power devices like PTZ cameras and wireless access points.

Question 2

What is the purpose of Automatic Gain Control (AGC) in a telephone system?

Accepted Answer

Normalize audio levels so quiet and loud voices are heard equally

Answer

AGC automatically adjusts the gain of incoming audio signals so that voice levels remain consistent regardless of the speaker's volume.

Question 3

In a structured cabling installation, where should voice patch panels be terminated to allow easy moves, adds, and changes?

Accepted Answer

At the MDF/IDF on a 110 or RJ-45 patch panel

Answer

Terminating voice pairs at a centralized patch panel in the MDF/IDF allows technicians to reconfigure circuits with short patch cords without re-pulling cable.

Question 4

What happens to VoIP calls when the IP network goes down if the phones have a PSTN analog backup (POTS survivability) configured?

Accepted Answer

Calls are routed over the analog PSTN lines automatically

Answer

PSTN survivability allows VoIP systems to automatically fail over to analog POTS lines so that inbound and outbound calling continues during an IP network outage.

Question 5

Which SIP response code indicates that a called party is temporarily unavailable (e.g., phone is off or unregistered)?

Accepted Answer

480 Temporarily Unavailable

Answer

SIP response code 480 (Temporarily Unavailable) indicates the endpoint exists but cannot accept calls at this moment, often because the device is unregistered.

(VDV) Voice Data Video Technician Certified Practice Test

(VDV) Voice Data Video Technician Certified Practice Test

VDV Voice Systems 5